Heat-treating apparatus



1934. A, N. LINDBERG HEAT TREATING APPARATUS Original Filed Dec. 19,1932 3 Sheets-Sheet l 11, ,934- A. N. UNDBERG 1,983

HEAT TREAT ING APPARATUS Original Filed Dec. l, 1932 s Sheets-Sheet 2 Dw1 1934. A. N. LINDBERG 1,933,551

HEAT TREATING APPARATUS Original Filed Dec. 19, 1932 I5 Sheets-Sheet 3P2 ."llll 8 I so @Zflm Z Patented Dec. 11, 1934 PATENT OFFICEHEAT-TREATING APPARATUS Axel N. Lindberg, Evanston, Ill.

Application December 19, 1932, Serial No. 647,938 Renewed February 28,1934 22 Claims.

This invention relates to an apparatus which is designed particularlyfor the heat-treatment of tubular shafts and rods, such as are used foraeroplane struts, golf club shafts, fishing rods, and for various otherpurposes. More particularly, the present improvements have to do withcertain co-related mechanisms by which a plurality of shafts aresuccessively fed into a furnace for heat-treatment, are removed from thefurnace and quenched immediately, and are then discharged into a chuteor other receptacle, all these operations following one upon anotherautomatically in timed relation without requiring special control orattention on the part of a human operator.

A heat-treating mechanism having the improved mechanisms as hereinafterdisclosed is simple and susceptible of being operated with speed andcertainty, and, in addition, assures a uniform heat-treatment andimmediate succeeding quench at every point over the treated shaft.

A suggestive embodiment of this invention is illustrated in theaccompanying drawings in the manner following:

Figure 1 is a side elevation of the combined charging and ejectingmechanism, the furnace, and the receiving jig, together with the kickermechanism by which each shaft in turn is removed to a chute or otherreceptacle after being quenched;

Fig. 2 is an enlarged transverse section on line 2-2 of Fig. 1;

Fig. 3 is a detail in section on line 3 of Fig. 1;

Fig. 4 is a central longitudinal section through the valve control forthe cylinder mechanism;

Fig. 5 is a section on line 5 of Fig. 1;

Fig. 6 is a detail in section on line 6 of Fig. 5;

Fig. 'l is a broken longitudinal section through the furnace andassociated mechanism at opposite ends thereof; v

Fig. 8 is a detail in longitudinal section through the shaft receivingjig and kicker mechanism associated therewith;

Fig. 9 is a-detall in-section on line 9 of Fig. 1; and

Fig. 10 is a detail in plan of the carriage body forming part of theejector mechanism.

The several operating units of my improved apparatus will now bedescribed in detail.

The furnace The furnace F herein shown is in the form of a revolvablebarrel formed with a series of chambers 0 open at both ends of the,barrel. These chambers, of which eight may be" a convenient number, arespaced equidistantly from the axis of the barrel and from each other,as, for example, 45". The furnace may be constructed of inner and outerrefractory units 14 and 15, respectively, (see Fig. 2) surrounded by aprotecting jacket. These refractory units are desirably in spacedrelation to provide passages 16 which interconnect the several chamberswhereby to promote a uniform interchange of heat. Suitable heating coils18 and 19 are.provided within the inner and outer refractory unitswhereby to heat the chambers between them. Electrical connections extendfrom the heating coils to collector rings 20 and 21 arrangedcircumferentially of the barrel to receive contact from brushes 22 and23, respectively, which are in connection with a source of electriccurrent. From the ends of the barrel which are desirably reinforced byheads 24 are extended trunnion shafts 25 journaled in bearings 26carried upon a framework 27 which may be rested upon a fioor or otherbase.

Means are provided for imparting to the rotatable furnace anintermittent index movement. As suggestive of a mechanism for thispurpose, the furnace barrel may be equipped with ratchet teeth 30arranged circumferentially at one end thereof. In operative relationwith the ratchet .teeth is a pawl 31 carried at one end of an arm 32which is pivoted to the proximate barrel trunnion. Extending from thearm is an -adjustable link 33 pivotally joined at 34 to a bell cranklever 35 which is fulcrumed at 36. The power end of this lever is shownas equipped with a roller 37 which tracks in a cam groove 38 formed in adisk 39 mounted fast on a control shaft 40 to which power is transmittedfrom any suitable source. The shape of the cam groove is such that at apredetermined point a quick oscillating movement is imparted to the bellcrank. The extent of the bell crank movement is suflicient to rotate thebarrel through the distance separating adjacent chambers, 'i. e. in theconstruction illustrated.. Any suitable detent device (not shown) may beemployed to arrest movement of the barrel when its rotation hascontinued through the intended distance.

The charging andeiecting mechanism In parallelism with the axis of thefurnace at the receiving end thereof is a track or guide 45 for wheels46 supporting a carriage 4"! which is I movable toward and from thefurnace. As shown, the operating means for the carriage consists of anendless chain 48 which is trained over idler pulleys 49 and 50 atopposite ends of the track or guide, and over a driving pinion 51 whichis made fast to a shaft 52 whereon is also carried a smaller pinion 53in mesh with a rack bar 54 one end' of which constitutes a piston rodform;- ing part of a piston mechanism P. As by pipes 55 and 56 extendingfrom opposite ends of the cylinder to a valve V, the operations of thepiston mechanism are controlled in timed relation with the heatingapparatus in its entirety in a manner to be later explained.

The carriage body supports one end of a hollow rod 60 which is alignedwith one of the chambers in the furnace barrel-the lowermost chamber inthe arrangement shown. This rod acts as an ejector to push out from thedelivery end of the furnace the shaft S which is in the lowermostchamber, this operation taking place as the carriage is advanced towardthe furnace. The ejector rod is rigidly mounted upon the carriage bodyso that its acting end is maintained in line with the furnace chamberthrough which it is to be advanced. If desired, the rod may beyieldingly supported to slide on the carriage through the use of a coilspring 61 which normally projects the rod to a forward position (seeFig. 7).

Slidably carried by a shelf 62 which extends forwardly from the carriagebody is a bracket 63 normally advanced against a stop 64 as by means ofa spring 65. This bracket pivotally supports at 66 a lever in the formof a bell crank having an upstanding finger 67 and a base 68. In theposition shown, the finger is rested against a stop 69 which sustainsthe finger against swinging rearwardly beyond the vertical. When thecarriage is in its retracted position, as shown in Fig. 1, a stationarycam 70 engages with the base of the bell crank lever to restore thefinger to upright position following its forward swinging movement whichtakes place during each return of the carriage to starting position.

The finger is located at one side of the ejector rod in line with thenext chamber to the left, as indicated in Fig. 2, so as to be engageablewith the end of a shaft S that is to be introduced intothat chamber. Asupply of such shafts may be contained in a hopper H whose bottomterminates in a well '11 forming a support for a single shaft, or apluarlity of shafts in vertical alignment. The bottom wall of the wellis slotted centrally at '72 for the length of the hopper, but the widthof this slot is insufilcient to release therethrough any of the shaftsthat are contained in the hopper. j The finger, when moved to verticalposition at a point rearwardly of the hopper, (see Fig. 1) is alignedwith the well so as to move through the slot when the carriage isadvanced (see Fig. 9), thereby engaging the proximate end of thelowermost shaft contained in the well to advance the same into thealigned chamber 0 of the furnace. Having advanced to its limit, as shownin Fig. 7, the moved shaft is deposited within the furnace so as to bewholly contained therein for heat treatment over a predetermined timeinterval. At the moment that the carriage reaches its extreme forwardposition, as shown in Fig. 7, it is possible for the bracket whereon thefinger is supported to slide back slightly, as required, in order thatthe parts may be mutually accommodated in this relationship. On thereturn movement of the carriage, the finger will swing forwardly uponengaging with the forward end of the next succeeding shaft which dropsinto lowermost position within the well, and the finger is accordinglyfree to slide along under the hopper without interference. Upon reachingits opposite extreme position shown in Fig. l, the finger is againrestored to vertical position by the cam 70 so as to be'positioned forengagement with the shaft next to be charged into the furnace. It is tobe noted that the operation of charging the furnace with a fresh shaftproceeds simultaneously with ejection of a heated shaft, both beingaccomplished by movements of one and the same carriage whereon aremounted the respective devices for these purposes.

The carriage is operated by mechanism P which is controlled by a valveV, such, for example, as is indicated in Fig. 4. Here I have shown ahousing containing a plug 75 having an operating stem '76 upon which iscarried a mutilated pinion 77. The plug is provided with two separatedaxial chambers 78 and 79. From the chamber 78 leads a radial port 80 andfrom the chamber 79 is extended a radial port 81, each port beingopposite an opening 82 when the plug is rotated to the position shown inFig. 4. Connected to one of these openings is the pipe 55 leading to oneend of the cylinder 83 and to the other opening is connected the pipe 56leading to the opposite end of the cylinder (see Fig. 1). From thechamber 78 other ports 84 communicate with an annular passage 85extending around the plug opposite an opening 86 to which is' connecteda pipe 87 lead-- ing to a source of fiuid under pressure. Likewise aseries of ports 88 extends radially from the chamber '79 to communicatewith an annular passageway 89 which is opposite a second opening 90 withwhich connects a pipe 91 through which fluid is exhausted from thevalve. The arrangement of the ports is such that successive intermittentmovements of the valve plug will open communication for fluid underpressure to pass into the cylinder 83 first at one end and then at theother to reciprocate the rack bar 54 and with it the carriage 4'7. j

Operation of the valve is controlled by a mutilated gear 92 carried uponthe control shaft 40. This gear is in mesh with the mutilated pinion7'7, and the interrupted arrangement of the teeth on these meshingelements is such that the-valve will be rotated through 90 degrees withintermissions correctly timed for (1) advance of the carriage, (2) pauseat the end of its forward movement, (3) return movement of the carriage,and (4) pause before repetition of this cycle.

The jig mechanism At the delivery end of the furnace, and in line withthe lowermost chamber from which a heated shaft is ejected by the rod60, a jig J is positioned. This jig is constructed to provide a seat forthe shaft; and, for a tapered shaft, such as is illustrated in thedrawings, the seat is desirably similarly tapered. The final position ofthe shaft within the jig may accordingly be determined by the fit of theshaft within its seat. The jig may also be slightly shorter than theshaft, so that the smaller end of the latter 'will project slightlybeyond the proximate end of the jig in a position to receive thrust froma kicker mechanism which will presently be described. The opposite shaftend may, if desired, remain protruded slightly beyond the proximate endof the jig, as shown in Fig. 7. When so related, it is possible to treata shaft having a flare or bell at its larger end, this being a formationwhich commonly results from the drawing operations resorted to inproducing the shaft.

In the construction shown, the jig is piIotally mounted at upon abracket 96 upstanding from a table or support 97. This pivotal supportfor the jig is located somewhere between its two ends, so that swingingmovement of the jig from the horizontal will cause the receiving end ofthe jig to drop below the proximate end of the furnace barrel while itsopposite end is raised sufficiently to position the proximate protrudingend of the shaft in operative relation to the kicker mechanism. When sotilted, as indicated in Figs. 1 and 8, the larger end of the jig liesopposite a chute 98 into which the several shafts, as dischargedsuccessively from the jig, are received. With each tilting movement ofthe jig, an upward thrust is exerted upon a stem.99 which is extendedloosely through the horizontal arm 100 of a bell crank lever having apivotal mounting at 101, the

lever being formed with a depending arm 102 the free end of which isutilized as a kicker for striking the proximate protruding end of theshaft within the jig. So that the bellcrank lever may function properlyfor this purpose, I provide a catch 103 engageable with the 'free end ofthe lever arm 100. The catch which is pivoted at 104 is normally held inengaging position by a spring 105. Extending from the catch is an arm106 adapted to be engaged by a collar 107, which is fixed on the stem99. A spring 108 encircling the stem is compressed between the collarand the. horizontal arm of the lever beyond which. is a stop-head 109 atthe stem end. In the inactive position shown in Fig. 1 the spring isexpanded to hold the lever arm against the catch, the striking end ofthe lever being thereby maintained away from the jig. With tiltingmovement of the jig, however, its rearward end is elevated to compressthe spring as the collar 107 is raised. With completion of thismovement, the collar engages the arm 106 to trip the trigger, therebyreleasing the kicker lever which, in response to tension 'force of thespring, is operated to kick the proximate end of the shaft and so removeit from the jig into the chute. In this manner, the jig is cleared forthe reception of the next succeeding shaft which is advanced thereintofrom the furnace.

According to the construction disclosed, the kicker mechanism isactuated and operated through movements of the jig alone; From thecontrol shaft are extended connections timed to operate with each indexmovement of the furnace barrel, by which to tilt the jig in the mannerexplained. As a convenient mechanism for this purpose, I have shown inFig. 2 a pair of links 110, 111, one pivoted to the jig at 112 near itsreceiving end, and the other pivoted at 113 to a fixed support, the twolinks being interconnected at. 114 to provide a toggle joint. As by anadjustable link connection 115, the toggle is joined at 116 with a link117 having a pivotal mounting at 36. Intermediately of its ends,'thelink- 117 may be provided with a roller 118 which tracks in a cam groove119 in a disk 120 carried fast on the control shaft 40, The form andarrangement of this cam is such that at a given point in the rotation ofthe control shaft, timed to follow after delivery into the jig of ashaft from the furnace, the jig will be swung down, whereby itsreceiving end is disposed below the furnace; at this juncture the kickeris actuated to eject the shaft from the jig into the chute as alreadyexplained.

The quenching mechanism The mechanisms thus far described provide forthe successive charging of shafts into the furnace and simultaneouslyfor the removal of other shafts from the furnace; for the delivery intothe jig of each shaft so discharged from the furnace; forthe-repositioning of the jig shortly after the shaft is receivedtherein; for the ejection from the jig of the received shaft promptlyupon repositioning of the jig; for the return movement of the carriagetogether with-its shaft charging and ejecting mechanism, and also of thejig; and for an index movement of the furnace about its own axisfollowing this cycle of operations. These several movements are timed tofollow closely one upon another. It remains now to describe thequenching mechanism by which the heat-treated shafts are quickly cooledin a uniform manner with a minimum of delay following their dischargefrom the furnace. I

The ejector rod 60 is provided at its acting end with a nozzle having aplug about which are formed spiral grooves 126 through which a stream ofquenching. fluid is forced as and when discharged from the nozzle. Theshape of the nozzle is such as to interfit with the proximate end of theshaft which, as shown in Fig. 7, remains desirably protruded for aslight distance from the jig. The nozzle remains fitted to the shaft upto the point that movement of the latter is arrested by its seatingfirmly within the jig, and thereupon this interfit becomes even moreclose, due to the forward projection of the rod by the spring 61 whenthe carriage is advanced to its limit. 'At the rearward end of the rodis a T-head 130 providing two passages in communication with the mainpassage through the rod. Each branch passage is valve-controlled at 131,and is connected as by flexible tubing 132, one with a source ofquenching fluid under pressure, and the other with a source of air underpressure.

Referring now to Fig. 61 have here shown one of the valves 131 which maybe of conventional type, in that it comprises a plug 135 carried at oneend of a stem 136 around which is a coiled spring 137 exerting oppositethrusts against a packing gland 138 and a head 139 which is carried atthe end of the stem. In the extreme forward position of the carriagethese two valves are brought into adjacent relation with a shaft 140having two cams 141 and 142. One of these cams is in operative relationto the head 139 of the stem 'of one valve, and the other cam issimilarly related to the other companion valve. The cam shaft issuitably connected in driven relation to a mutilated gear 145 mounted onthe control shaft 40. The interruptions in the teeth of the mutilatedgear are so arranged that the cam shaft is rotated through 360 for abrief period at a proper point in the cycle of operations, viz., whenthe carriage is advanced to the limit of its forward movement. Thetiming of the cam shaft operation may be otherwise arranged, however,depending upon the exact point in the cycle when it is desired that thetwo valves 131 should be operated. In the construction shown, the cam141 opens the valve controlling the discharge of quenching fluidimmediately upon the compleafter, immediately, or with such pause as isdesired, the remaining cam 142 operates the comblows out from the rodand shaft any quenching fluid remaining therein. The fluid so forced outfrom the shaft is caught in a hood 146 for return to the supply source.

At this point it is to be noted that the quench is'applied to the shaftimmediately upon its removal from the furnace. The movement of thecarriage is preferably timed for speedyoperation,

so that the time interval required for shaft movev entire shaft surface,both circumferentially and from end to end, is subjected to the coolinginfluence at practically one and the same moment. This is accomplishedby-discharging the quench in the form of a whirling stream which isprojected from the nozzle with sufficient force to strike the innersurface of the shaft at every point from end to end at one and the samemoment, or substantially so. As the walls of the shaft are relativelythin, it is unnecessary that the quench be continued for more than avery brief period, and the air which follows immediately upontermination of the quench cleans out the shaft so as to prepare theshaft for prompt removal from the jig in the manner already explained.This operation by which the shaft-is kicked out from the jig, followsimmediately upon the quench, and proceeds during return movement of thecarriage, so that there is no loss of time. The restoration of the jigto receiving position follows immediately upon ejection of the treatedshaft, and during index movement of the furnace to its next position.

Operation in its entirety may function smoothly, continuouslyand.efliciently.' Inthe heat-treating of shafts these are importantconsiderations because the quench should desirably follow immediatelyupon removal of the shaft from the furnace, otherwise an inferiorproduct will-result.

The several units which have been incorporated into the apparatushereinbefore described may accordingly be constructed to operate inconjunction with each other by suitable mechanisms of which a suggestiveembodiment has been indicated, but obviously numerous changes in detailsof construction and arrangement of parts may be made as found desirable,without departing from the principles of this invention, as defined bythe claims following.

I claim: j- 1. In aheat-treating apparatus, the combination of a furnaceopen at both ends adapted to i receive therein a shaft, a. jig forreceiving the shaft disposed opposite the opening at one end of thefurnace, and a combined ejector-nozzle movable through the opening atthe opposite furnace end for pushing the shaft into the jig and thereapplying a quench to the shaft.

2. In a heat-treating apparatus, the combination of a furnace open atboth ends adapted to receive a shaft, a jig opposite the opening at oneend of the furnace for receiving the shaft which is advanced thereintofrom the furnace, an ejector-nozzle fitted to the shaft end adjacent theopposite end of the furnace for removing the shaft therefrom intothejig, and valved connections from the ejector-nozzle to (1) a source ofquenching fluid under pressure and (2) a source of air under pressurepermitting selectively passage of quenching fluid and/or air through theejector-nozzle to the shaft.

3. In a heat-treating apparatus, the combination of a furnaceopen atboth endsfor the reception of a shaft, a jig opposite the opening at oneend of the furnace for' receiving the shaft when moved thereinto, anejector-nozzle at the opposite end of the furnace movable thereinto todisplace the shaft therefrom, means for guiding the ejector-nozzle in aline coincident with its own axis, means for limiting theadvance of theejector-nozzle to a point at which the shaft is seated in the-"jig, andmeans for delivering a quenching fluid through the ejector-nozzle andover the surface of the shaft while seated within the jig.

4. In a heat-treating apparatus, the combination of a furnace open at.both ends for the reception of-a shaft, an ejector movable through thefurnace from one end thereof to eject the shaft from'the oppositefurnace end, a jig opposite the delivery end of the furnace adapted toreceive the shaft ejected therefrom, and means for discharging the shaftfrom the jigh j 5.- In a heat-treating apparatus, the combination of a.furnace open at opposite ends for the reception of a shaft, an ejectormovablethrough one end opening of the furnace for ejecting the shaftfrom the opposite endthereof, a jig at the delivery end of the furnacefor receiving the shaft ejected therefrom, means for discharging theshaft from the jig, and coordinated operating mechanisms for theejectorand jig.

6. In a heat-treating apparatus, the combination of a furnace havingopposite end openings through which a shaft is movable, a combinedcharger and ejector at one. end of the furnace adapted simultaneously tointroduce a new shaft thereinto and to remove a heated shaft therefrom,and a jig at the delivery end of the furnace positioned to receive theheated shaft ejected therefrom. 1

7. In a heat-treating apparatus, the combinathrough which a shaft maypass, a combined charger and ejector at one end of the furnace forsimultaneously introducing a new shaft thereinto and for removing aheated shaft therefrom, a jig at the delivery end of the furnace forreceiving therein the heated shaft removed from the furnace, and akicker mechanism associated with the jig for removing therefrom theshaft after being cooled therein.

8. In a heat-treating apparatus, the combination of a furnace havingopposite end "openings through which a shaft may be passed, a combinedcharger and ejector-nozzle at one'end of the furnace adaptedsimultaneously to feed thereinto a new shaft and remove therefrom aheated shaft, a jig at the opposite end of the furnace for receivingtherefrom the heated shaft, and means for applying to the shaft while inthe jig a stream of quenching fluid delivered through the ejectornozzlewhile still advanced through the furnace.

9. In a heat-treating: apparatus, the combination of a furnace havingopposite end openings through which a shaft may be passed, a combinedcharger and ejector nozzle at one end of the furnace for simultaneouslyfeeding thereinto a new shaft and ejecting therefrom a heated shaft, ajig at the opposite end of the'furnace for receiving therefrom theheated shaft,-a connection from the ejector-nozzle to a source ofquenching fluid under pressure, and means operable with advance of theejector nozzle to apre-determined point for releasing the quenchingfluid for discharge through the nozzle upon the surface of the shaft.

10. In a heat-treating apparatus, the combination of a furnace havingopposite end openings through which a shaft may be passed, a combinedcharger and ejector-nozzle at one end of the furnace for simultaneouslyfeeding thereintoa new Qiaft and ejecting therefrom a heated shaft, ajig at the opposite furnace end for receiving therefrom the heatedshaft, connections from the ejector-nozzle to a source of quenchingfluid under pressure and to a source of air under pressure, and meansoperable upon advance .of the ejector-nozzle through a pre-determineddistance for releasing, first, quenching fluid through the nozzle fordelivery upon the walls of the shaft, and, second, air through thenozzle for cleansing the quenching fluid therefrom and from the shaft. v

11. In a heat-treating apparatus, the combination of a furnace 'havingopenings at opposite ends through which a shaft may be passed, a jig atone end of the furnace adapted to receive a shaftwhich is ejectedtherefrom, means movable through the opposite end of the furnace formoving the shaft therein into the jig, means for applying a quench tothe heated shaft contained within the jig, and means for discharging thequenched shaft from the jig.

12. In a heat-treating mechanism, the combination of a furnace havingopenings at opposite ends through which a shaft may be passed, a jigmounted at one end of the furnace adapted to receive a shaft which isejected therefrom,

means movable through the opposite end of the furnace for moving theshaft therein, means for shifting the jig from shaft receiving position,

means for quenching the shaft while retained within thejig, andmeans'for discharging the shaft from the jig following its shiftingmovement from shaft receiving position.

13. In a heat-treating apparatus, the combination of a furnace havingopenings at opposite ends through which a shaft may be passed, meansmovable through the opening at one end of the furnace for ejectingtherefrom a heated shaft, a jig at the opposite furnace end forreceiving the shaft so displaced from the furnace, means for applying aquench tothe shaft while retained within the jig, and means fordischarging the quenched shaft from the jig.

.14. In a heat-treating apparatus, the combination of a furnace havingan opening through which a shaft may be passed, a jig ODPQs'ite theopening adapted to receive therefrom a'heated shaft, an ejector.engageable with the shaft for quench upon the shaft coincidentally witharrest of shaft movement within the jig.

16. In a heat-treating apparatus, the combination of a rotatable barrelfurnace having a plurality of equally spaced chambers extending from endto end of the furnace, an ejector at one end of the furnace movablethrough one chamber thereof, a jig at the opposite furnace end in linewith the ejector adapted to receive a heated shaft displaced from thefurnace by the charger,- and means for quenching the shaft whileretained within the jig.

1'1. In a heat-treating apparatus, the combination of a rotatable barrelfurnace having a plurality of chambers extending from end to end of thefurnace, an ejector at onevend of the furnace movable through one of thechambers thereof to displace a shaft therefrom, a jig at the oppositefurnace end in line with the ejector for receiving the ejected shaft,and coordinated mechanism for operating the ejector for discharging theshaft from the jig, and for thereafter imparting to the furnace an indexmovement.

18. In a heat-treating apparatus, the combination of a rotatable barrelfurnace having a plurality of chambers extending longitudinallytherethrough, an ejector at one end of the furnace movable through achamber thereof, a jig at the opposite furnace end, in line with thechamber through which the ejector is moved, adapted'to receive a shaftdisplaced from the furnace 'by the ejector, means for applying a quenchto the shaft while retained in the jig, and co-ordinated operatingmechanism for advancing the ejector through the furnace, for releasingthe quench upon the shaft, for discharging the shaft from the jig, forwithdrawing the ejector, and for imparting to the furnace an indexmovement.

19. In a heat-treating apparatus, the combination of a rotatable barrelfurnace having chambers extended therethrough from end to end, anejector-nozzle at one end of the furnace having means by which it ismoved through a chamher thereof to dislodge therefrom a heated shaftcontained therein, a jig at the opposite furnace end, in line with thefurnacev chamber from which the shaft is removed, adapted to receive theshaft, means for releasing through the ejector-nozzle a stream ofquenching fluid for delivery upon the shaft while retained within thejig, means for discharging the quenched shaft from the jig, andco-ordinated mechanisms for operating the several means aforementioned.

20.In a heat-treating apparatus, the combination of a rotatable barrelfurnace having a plurality of chambers extended therethrough from end toend, a carriage at one end of the furnace mounting a charger and anejectornozzle adapted for movement through two of the through' which theejector-nozzle is moved, and co-ordinated mechanisms for advancing thecarriage whereby simultaneously to introduce a new shaft into onechamber of the furnace and to remove a heated shaft from anotherchamberthereof into the jig, for withdrawing the carriage together with thecharger and ejector-nozzle, and for thereafter imparting to the furnacean index movement.

21. The -method of heat-treating a tubular shaft which-consists in firstheating the shaft in a furnace, in then removing the shaft from thefurnace by thrust from an ejector-nozzle fitted to one end of the shaft,and, finally, in releasing through the ejector-nozzle while still fittedto the shaft a stream of quenching fluid AXEL N. LINJSBERG. 15

